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Full text of "Alaskan glacier studies of the National Geographic Society in the Yakutat Bay, Prince William Sound and lower Copper River regions"

306                                ALASKAN GLACIER STUDIES
the oldest shrubs growing in this barren zone were from 8 to 10 years old.   Outside morainic area are mature alder thickets and some spruces.
Barnard, Holyoke, and. Smaller Glaciers. Barnard and Holyoke Glaciers, smaller cascading glaciers than most of those toward the north, end a thousand feet or more above the fiord. Gilbert alludes to them as "small glaciers occupying alcoves on the mountain front but ending far above the water." South of them are three small cliff glaciers, resting on ledges at the base of Mt. Emerson. There are also small ice masses between several of the cascading glaciers to the north.
Barnard Glacier is a clean, crevassed ice tongue, with no medial or lateral moraines. It heads in a large cirque and connects with an irregular ice mass on a shelf to the north. There is a bare rock slope at the end of the glacier which has small terminal lobes and terminates on the lip of its hanging valley. Two streams descend from the terminus. Mature spruce forest extending from the fiord well up toward the glacier terminus indicates that Barnard Glacier has not descended much farther toward the fiord for a century or more; but a barren zone between the ice and forest, present in 1899 as well as in 1910, proves that it has been retreating in recent years. Between 1899 and 1910 there was an advance of the south lobe down the lip of the hanging valley, and a slight advance of the north lobe, while between the two lobes an ice block talus was formed. We are inclined to believe that the advance was still going on in 1910.
Holyoke Glacier, which heads in a large cirque and is fed by two glaciers from a small cirque on the south, has two weak medial moraines extending from spurs between its south tributaries. There are no lateral moraines, but there are a few morainic patches along the -terminus. The glacier is longer than Barnard, and extends out over the lip of its hanging valley. In 1910 the glacier nowhere extended to the borders of its barren zone, and the mature spruce forest between the small terminal barren zone and the fiord demonstrates that it has not extended beyond this barren zone for a century or more. No distinct signs of recent advance were seen.
The cliff glaciers on the ledges south of Holyoke Glacier present no unusual features. There is every reason to believe that they are self-sustaining, and in one case a projecting lobe extended down from the shelf.
Yale Glacier. Yale Glacier has a known length of seven miles, and is probably over twice that length. Its width varies from a mile and a quarter to two miles. In its lower portion the glacier slopes at the rate of 600 to 700 feet per mile, attaining an elevation of 2600 feet three miles and a half from the front, and ascending gradually to 6000 or 7000 foot cirques east of Mt. Glenn.1                                                         '
The Yale Glacier, though wider at the terminus, is probably not as long as the Harvard, It terminates in the Yale Arm of College Fiord, with an unusually irregular front, the south side of the glacier extending If miles further down the fiord than the north side. This terminal cliff is between 200 and 300 feet high. There are well-marked lateral moraines, but no medial moraines (PL CXXIV, A). In the absence of a number of large tributaries which supply quantities of ice, and lateral moraines that become medials, Yale Glacier differs very decidedly from Harvard Glacier. The distant tributaries are rather small glaciers cascading from extensive nev6 fields on the mountain slopes. In the lower part of the glacier there are not many tributaries on the northwestern side, contrasting with a considerable number which descend on the southeastern
i Named in 1910 for Lieut. E. F. Glenn of the U. S. Army.